Apparatus for the distillation of solid carbonizable fuel



Feb. 2, 1937. E. M. SALERNI 2,069,421

APPARATUS FOR THE DISTILLATIQN SOLID CARBQNIZABLE FUEL Filed Oct. 4, 1933 2 Sheets-Sheet 1 Feb- 2, 1937 E. M. SALERNI' APPARATUS FOR THE DISTILLATION OF SOLID CARBONIZABLE FUEL 2 Sheets-Sheei 2 I Filed Oct. 4, 1933 Patented Feb. 2, 1937 UNITED STATES PATENT OFFICE APPARATUS FOR THE DISTILLATION 0F SOLID CARBONIZABLE FUEL 0 ompany Application October 4, 1933, Serial No. 692,173 In France October 6, 1932 2 Claims.

The present invention relates to low temperature carbonization furnaces of the continuously acting type in which the heating is external and the material is continually kneaded or mixed.

The furnace which constitutes the subject matter of the present invention, is characterized broadly by a high unitary output or capacity which is obtained by grouping, in a very confined space, a certain number of like elements and by carrying out in each of these elements a system of kneading or mixing and propulsion or feeding adaptable to all materials even such as agglomerate and swell.

According to the present invention, each element is of tubular shape or a modification of that shape, containing a central shaft provided with kneading or mixing and propelling or feeding devices, a certain number of these elements being grouped in a single heating chamber in horizontal planes and arranged one above the other, somewhat hke the tubes in a tubular steam boiler, and passages for the circulation of the heating gases being arranged between the different elements. This grouping of the different elements in nests or bundles permits of a large active heating surface being obtained within a small space.

The elements open at each end into a common enclosure or space which serves at the same time as a support for the said elements, and at the points of support, gastight joints are provided which ensure the free expansion of each element under the action of heat. The enclosures or spaces may serve at the same time as headers or collectors for the gases and vapours of a tarry nature yielded up during the heat treatment, outlet or discharge pipes being also provided.

The common enclosures or spaces may be divided up into compartments horizontally so as to ensure the guiding of the material from one stage to the other in a zig-zag manner, and they may also be provided with mechanical devices for facilitating the passage of the material towards the next lower stage or its discharge towards the outlet. These mechanical devices, which are constituted by scrapers or paddles of suitable form, may be placed either on the kneading or mixing shafts which pass through the chamber, or on additional and special shafts.

On each shaft, in the vicinity of the outlet from each element, there may be mounted sectors of suitable dimensions, which revolve with the shaft and the function of which is to ensure a constant coefficient of filling or charging of the elements which shall also be regular, while maintaining a fixed level for the material under treatment in each of the said elements. These sectors may be provided with scraper devices.

In order that the said invention may be clearly understood and readily carried into effect the same will now be described more fully with reference to the accompanying drawings which show by way of example one embodiment of the invention, and in which:

Figure 1 is a longitudinal section of a furnace constructed according to one mode of carrying the invention into effect, said section being taken through the kneading or mixing shafts.

' Figure 2 is a transverse section taken on the dotted line A--B of Figure l.

Figure 3 is a transverse section of a modified form of element constituted by the combination of three circular elements, and Figure 4 is a transverse section of an element formed by the combination of two circular elements, these modifled elements being used, when desired, in lieu of the elements shown at Figures 1 and 2.

The drawings show a three-stage furnace, each stage comprising three horizontal and parallel elements, each element i'being supported at its ends by the internal walls of a two-stage common enclosure or space 2, space being provided for the entry where the enclosure or space 3 is connected to the charging device 4- and for the outlet where the enclosure or space 5 is connected to the discharging device 6.

Each element I is provided with a kneading or mixing shaft 7 which passes through the enclosures or spaces 2, 3 or 6 outside the furnace. The means employed for rotating the kneading or mixing shafts l is common and arranged at 9 and is provided with means for producing at any given stage, speeds different from those of the other stages.

Each shaft carries, inside the element, a series of paddles I!) of helicoidal or like form arranged in such a way that the whole of these paddles form a screw of a pitch conducive to the feeding forward of the material from the entry towards the outlet of each element, while also serving to stir and scrape the material from the sides of the tubular elements. Towards the outlet from each element the shaft carries sector-like segments l I which rotate with the shaft, all the segments on the shaft when seen in projection, covering a solid circular space.

The elements H are segments of a circle and are vertically disposed and located at suitable distances apart. Only one sector-like segment may be provided at the same point on the shaft, the other single segments which are also provided at other points along the shaft being staggered or displaced relatively to one another so that the several segments in end view present the appearance of a circle. It is preferred, however, to constitute each element H by two, three or four sector-like segments. The sector-like segments I l are staggered or displaced relatively to one another so as to allow the solid material to pass gradually to the outlet end of each tubular element, while at the same time insuring a constant co-efiicient of filling or charging of the elements which is regular, and simultaneously maintaining a fixed level for the material undergoing treatment in each of the said elements.

The fuel employed for heating purposes is consumed on a grate or in burners l2, and passes into the combustion chamber l3, whence the hot gases are distributed throughout the passages l4 and finally pass away into the chimney I5.

The material, fed into the furnace through a charging hopper, spreads itself out along the entrance space which is below the hopper, whence the mechanical devices feed it forward and distribute it over the three elements of the upper stage. At the end of this stage the material passes into the common enclosure or space which represents the outlet for the upper stage and the entrance for the next lower one. The gases and vapours evolved escape through the headers or collectors l6 and pass onto a cooling and condensing apparatus. In order to facilitate the passage of the material towards the next lower stage or its discharge towards the outlet, the shafts 7 adjacent their ends have secured thereto the paddles H which are spaced from the adjacent ends of the tubular members I.

The passage of the material which is indicated by the arrows in full lines terminates at the bottom of the last stage where the material, carbonized to the desired degree, passes through a cooling and discharging apparatus. The heating gases follow the course indicated by the dotted arrows.

The construction and arrangement of each element may be modified, as also that of the kneading or mixing and propelling or feeding device. A single kneading or mixing device is provided in the case of an element of tubular cylindrical form, while, when several kneading or mixing devices are used a more complex form of tubular element is required, as shown at Figs. 3 and 4, depending on the particular type of kneading or mixing device employed, but adopting in each case form for the element which offers the maximum surface available for heat interchange, so as to permit the kneading or mixing devices to scrape the internal walls of the element while at the same time fulfilling their function of propulsion or feeding.

To facilitate the treatment of the materials in an agglutinated or swollen state, one or more modifications or additions may be made in and to the system of kneading or mixing and of pro-- pulsion or feeding. For example, by modifying the pitch of the screw formed by an imaginary line connecting the paddles or other kneading and propelling devices on one and the same shaft, this modification serving to increase the propulsion or feed of the material in the zone in which it agglutinates or swells up.

The speed of rotation of the kneading or mixing shafts may be varied in the elements of a stage in which the swelling or increase in volume of the product takes place. This change of speed can, however, only be employed in cases where there is installed a supplementary system of kneading or mixing functioning in the zone in which the material increases in volume and consequently superimposed on the kneading or mixing devices designed for the treatment proper of the material, the effect of this modification being to propel forward the mass which exceeds the fixed level so that the product may be treated at a normal and definite rate, (see Figs. 3 and 4.)

It is to be understood that any one of these modifications and additions may be adopted not only on the type of apparatus which constitutes the subject matter of the present invention, but also on any other system provided with kneading or mixing and propelling or feeding devices.

The apparatus may be surmounted by a drying apparatus provided with plates over which the material is caused to travel by any kind of mechanical means, such for example, as transverse oars connected to each other by endless chains.

A number of furnaces or blocks of elements may be grouped side by side in batteries, and a space may be provided between contiguous blocks in which apparatus for removing dust from the gases or vapours before they are condensed, is arranged, an endless screw or the like being provided in the base of the chamber to remove the deposited dust.

I claim:

1. A low temperature carbonization retort furnace of the continuously acting type. in which the heating is external and the material is continuously kneaded, comprising a horizontally disposed tubular member positioned within the furnace, means for conducting the material into one end of the tubular member and for discharging the material at the opposite end of the tubular member, a shaft revolubly mounted in said tubular member, helicoidally shaped paddles nonrotatably secured to said shaft for feeding the material through the tubular member, non-propelling means secured to the shaft adjacent the discharge end of the tubular member for maintaining a substantially fixed level of the material in the tubular member during the operation of the furnace, means for actuating said shaft, and said non-propelling means including spaced segmental members circumferentially offset on said shaft relative to one another so that the several segments in end view have the appearance of a circle, and means for actuating said shaft.

2. A low temperature carbonization retort furnace of the continuously acting type in which the heating is external and the material is continuously kneaded, comprising a plurality of superposed horizontally disposed tubular members, means for conducting the material into one end of the upper tubular member, said furnace having a vertically disposed passage at its opposite cnd for establishing communication of the adjacent tubular members with each other, a shaft extending axially through each of said tubular members, helicoidally shaped paddles keyed to each of said shafts for feeding the material through the tubular member, said shafts adjacent their discharge ends having non-propelling means secured thereto for insuring a constant co-efficient of filling of the tubular members as the material is conducted from one tubular member to the other, said non-propelling means including spaced segmental members circumferentially oifset on each of said shafts relative to one another so that the several segments on each shaft in end view have the appearance of a complete circle, means secured to the ends of each shaft and spaced from the tubular member thereon for facilitating the passage of the material from each tubular member to its adjacent lower tubular member, and means for actuating said shafts.

EDOARDO MICHELE SALERNI. 

